Accepted Answer

I loaded my ClearOS 7.x in a similar way a year ago and hit a few issues. One thing was the change of network interfaces left a number of files with obsolete interfaces in the configs and also a few obsolete files. I working from memory, but try something like "locate ifcfg-". It should list a few files in /etc/sysconfig/network-scripts (or something like that). Some of those refer to the old interfaces from the machine where you loaded the disk. It is not "lo" and you should be able to identify the ones which belong to your current system (try an "ifconfig" if you can't). The rest (probably 2 if you did a basic gateway setup) refer to your old interfaces. Note the part of the file name after the "ifcfg-". Then do:

Tidy up anything you find. I think /etc/samba/smb.conf, /etc/clearos/network.conf and my firewall rules were an issue (especially since I'd done a 6.x backup and restored it into 7.x). Maybe there are more files. Restart any relevant services after tidying up.

Also do a "locate your_old_interface_name" and see which other files are hanging around. there are the ifcfg ones and also there will be some systemd arpwatch files.

For safety's sake you may want to back up any files you change or delete first - a config backup will do that for the files under /etc and a few other places.